Starfish

Have you ever wondered how a starfish can eat and digest their food? Starfish have unique

digestive systems. Their mouth is located on the underside of their body, and their anus on the

upper side of their body. They also have tube feet with tiny projections that enable them to move

and catch prey. When a starfish eats a clam, they will push their stomach out of their mouth and

into the clam, digesting it completely in its own shell. Starfish is the common name for their

group name “sea stars” and they are related to sea urchins, sea cucumbers, and brittle stars –

starfish are not fish at all. Starfish are predators and eat anything that they can come across,

making them important predators in the shallow ecosystem. In comparison to sharks and wolves,

starfish are keystone species. Without starfish, the ecosystem, in which they live, would

dramatically change. In an experimental removal of starfish on the west coast of North America,

resulted in a rapid increased growth of mussels that crowded out other species, and dominated

the community. Starfish in that ecosystem are important for keeping mussel populations low so

other species can flourish.

What happens when starfish are removed from the ecosystem video:

https://www.youtube.com/watch?v=rN5KzBVxNl4

References:

https://www.sciencelearn.org.nz/videos/41-role-of-starfish-in-the-ecosystem

https://science.jrank.org/pages/3758/Keystone-Species-Keystone-predators-herbivores.html